Scientists say that 90% of dengue cases could be slashed by artificially infecting mosquitoes.
Dengue viruses are spread to people by infected mosquitoes. But infecting the insects with Wolbachia bacteria blocks the dengue virus from replicating in mosquitoes and being transmitted between people, the international researchers said in a new study.
Wolbachia is found naturally in about 60% of insect species, including some mosquitoes, butterflies and moths.
“Dengue is a leading cause of illness and death among children across the globe,” said study lead author Lorenzo Cattarino, of MRC Centre for Global Infectious Disease Analysis at Imperial College London.
The team of scientists created the first worldwide map of dengue transmission intensity — a measure of how easily dengue is transmitted to people.
Using this map, they predicted the effectiveness of two methods of combating dengue, vaccination and the release of mosquitoes infected with Wolbachia.
In trials, scientists are infecting the mosquito species (Aedes aegypti) that carry dengue with Wolbachia and releasing them into areas where dengue is prevalent. The trials suggest the bacteria doesn’t pose a threat to animals or people.
Using available data and their new transmission intensity map, the study authors concluded that the release of Wolbachia-infected mosquitoes could eliminate nearly all cases of dengue worldwide.
They also assessed a newly licensed dengue vaccine that reduces the intensity of subsequent dengue infections. They concluded that the vaccine could reduce the number dengue cases by up to 30%.
The researchers noted that the vaccine reduces the risk of becoming severely ill, rather than lowering the risk of virus transmission.
“Our research not only produces the first world map of dengue transmission, but can act as a tool to inform the World Health Organization, local governments and policymakers on the effectiveness of prevention strategies, such as the release of Wolbachia-infected mosquitoes and vaccination programs,” Cattarino said in a college news release.
Dengue infects more than 100 million people each year, and it’s believed that half of the world’s population is at risk. The virus typically causes fever, headache, muscle and joint pain. In some cases it can lead to a life-threatening condition called hemorrhagic fever, a leading cause of death and serious illness among children in some Asian and Latin American countries.
There is no specific treatment for dengue. Prevention focuses on avoiding mosquito bites.
The study was recently published in the journal Science Translational Medicine.
The World Health Organization has more on dengue.